Vibrating screening apparatus

ABSTRACT

A vibrating screen frame includes a concentric cross timing shaft having an axially floating connection at its ends with rotary housings provided with counterweight assemblies. Bearing means mount the interior of the housings upon support means fixed to the frame and surrounding the cross shaft.

United States Patent [191 Johnson 1 Oct. 30, 1973 [54] VIBRATING SCREENING APPARATUS 2,884,790 5 1959 Lehman 209/366.5 x s 2,902,868 9 1959 F 74 87 [75] Inventor: Gerald m Forest Lake- 3,393,571 7/1968 74/37 Mlnn- 3,470,754 10/1969 Ferrara... 209/367 x V A ggg Bangfi n l Q to 2,267,143 12/1941 Soldan 209/366.5

[22] Filed: June 11, 1971 Primary ExaminerRobert Halper [21] Appl No 152,272 Attorney-Emory L. Groff et al.

[57] ABSTRACT [52] US. Cl. 209/364, 209/325 A vibrating Screen frame includes a concenmc cross [51] timing shaft having an axially floating connection at its [58] Field Of Search 209,325, 326, 329, ends with rotary housings provided i counter 209/339 367; 74/87 61 364 weight assemblies. Bearing means mount the interior of the housings upon support means fixed to the frame [56] References and surrounding the cross shaft.

UNITED STATES PATENTS 8 Claims, 2 Drawing Figures 2,599,496 6/1952 Soldan 209/366.5 X 2,847,860 8/1958 Porter 74/87 PATENTEDUCT 30 ms IIVVENTOR ,GERALD D. JOHNSON 614 i A ORNEY VIBRATING SCREENING APPARATUS This invention relates generally to a screening device, and more particularly, to a classifying or separating apparatus including improved high speed rotary drive means for producing an orbital movement in the apparatus.

The general operation of vibrating screens is well known to those skilled in the art. In most instances, one or more screen decks are supported between a box-like frame assembly which in turn is supported by any suitable resilient or spring cushion means. In certain of these installations, the oscillating or orbital motion is produced in the screen assembly by means of a rotatable transversely disposed eccentric shaft. With hearing means supporting the ends of the shaft, it will be understood that upon rotation thereof, the eccentric mass of the shaft produces the desired throw of the screening apparatus. Such an arrangement has several disadvantages, not the least of which is the initial cost of fabrieating the eccentric cross shaft itself. Additionally, the self-induced throw of the cross shaft as it is rotated necessitates the provision of a substantial vertical space within the frame assembly, thereby increasing the overall height of the screening apparatus irrespective of the number of screen decks therein. a

Contrary to the concept of the above-described apparatus, the present invention provides an improved arrangement utilizing a cross shaft of concentric construction having its end portions connected to rotary housings which in themselves are concentric but which carry a counterweight assembly. Suitable anti-friction bearing means within the rotary housings are supported upon a concentrically disposed tubular bearing support rigid with respect to the screen frame assembly. An important feature includes the attachment of the ends of the cross shaft to the rotary housing by means of a spline engagement permitting of free axial displacement of the cross shaft during the operation of the apparatus.

This axial floating arrangement precludes any axial loading of the bearings supporting the counterweighted rotary housings about the fixed bearing support carried by the screen frame assembly.

Accordingly, one of the objects of the present invention is to provide an imporved vibrating screening apparatus including a rotating cross shaft of concentric construction and having axially floating connections at its free ends.

Another object of the present invention is to provide an improved screening apparatus including a concentric cross timing shaft adjustably oriented at both ends with respect to concentric rotary housings provided with internal bearings supported upon a fixed tubular support member attached to the screen frame assembly.

A further object of the present invention is to provide a vibrating screen having a cross shaft supported at its ends by splined engagement with an arcuately adjustable sleeve and said sleeve may be selectively locked to a rotary drive housing having interior bearings carried by a fixed support attached to the screen asembly about the shaft.

With these and other objects in view which will more readily appear as the nature of the invention is better understood, the invention consists in the novel construction, combination and arrangement of parts hereinafter more fully described, illustrated and claimed.

A preferred and practical embodiment of the present invention is shown in the accompanying drawing, in which:

FIG. 1 is a vertical view, partly in section, of the present invention.

FIG. 2 is a fragmentary end elevation of the structure shown in FIG. 1.

Similar reference characters designate corresponding parts throughout the several views of the drawings.

Referring now to the drawing, particularly FIG. 1, it will be understood that the present invention relates to a specific bearing assembly as associated with rotary drive means including concentric and eccentric elements adapted to produce an orbital motion to a vibrating screening apparatus represented in the drawing by the screen frame side wall 1. The entire representation of a screening apparatus is purposely omitted from the drawing for reasons of clarity as it will be appreciated that any suitable type of conventional screening apparatus as is well known in the art may be combined with the concept of the present invention. Such screening apparatus include a box-like frame having a pair of oppositely disposed side walls 1 between which are supported one or more perforated plates or wire screen elements. The entire assembly is intended to be supported upon a stationary platform or surface by means of resilient elements such that a vibration produced within the assembly itself permits free movement of the assembly to accomplish its screening purpose.

The bearings, generally designated 2, may be utilized in any suitable numbers according to the size and load demands of the specific screening apparatus and are encased between an inner race 3, carried by and fixedly attached to the tubular bearing support 4, and a movable outer race 5. The tubular bearing support 4 is preferably cylindrical and includes an intermediate outer peripheral portion 6 tightly fitted within the bore 7 of a tube mounting plate 8 which is affixed to the screen frame assembly side walls 1 by any means such as the removable fasteners 9. The concentric outboard portion 10 of the tubular bearing support 4 extends from the mounting plate 8 axsufficient distance to accommodate the required number of bearings 2 and the associatcd apparatus to be described hereinafter. In view of the freestanding nature of the outer portion 10, the bearing support 4 extends in the opposite direction a sufficient distance to provide an inner or inboard portion 11 which is further anchored with respect to the screen frame side wall 1 by means of stabilizing plate 12 in turn fixedly attached to a horizontal support member 13 secured to the side wall 1. With the foregoing construction in mind, it will be seen that any rotary eccentric force directed upon the outer portion 10 of the bearing support 4 will be transmitted to the screen frame side wall 1 and thusthe .screen assembly, by means of the rigid attachment of the bearing support tube 4 to the screening apparatus.

Supported upon the exterior of the outer race 5 of the bearings 2 is a rotary drive housing, generally designated l4, and which includes the vertically disposed outside end wall 15 joined to a peripheral cylindrical wall 16 and an inside end wall 17. The center of the outside end wall 15 is provided with a tapered bore 18 within which is disposed a sleeve 19 provided on its exterior periphery with a mating tapered surface 20. The sleeve 19 includes a central cylindrical bore 21 provided with axially extending splines 22. Closing the outer opening of the sleeve 19 is an end plate 23 provided with a plurality of fasteners 24. passing therethrough and into tapped openings in the outside end wall of the drive housing 14. An additional opening is formed through the end plate 23 and is located on a radius from the center of the plate which is juxtaposed the outer face of the tapered sleeve 19. This opening 25 serves to provide locating or guide means during adjustment of the mechanism as will be described hereinafter.

Disposed within the fixed tubular bearing support 4 is a rotating cross timing shaft 26 having at opposite ends identical shaft stubs 27 of a lesser diameter and which are provided on their exterior surface with a plurality of longitudinally extending splines 28 mating with the splines 22 within the tapered sleeve 19. These mating splines are constructed to permit free axial displacement of the cross timing shaft 26 between the pair of oppositely disposed tapered sleeves 19, while at the same time insuring against any arcuate displacement between the timing shaft 26 and the two sleeves, as well as the rotary housings 14 rigidly attached to the sleeves. To minimize the expense of fabricating the timing shaft 26 and also to reduce the resultant weight thereof, this shaft is preferably constructed from tubular stock as shown in the drawing. An additional point to be noted is that the total axial length of the shaft and its stub portions must be less than the distance between the inner faces of the oppositely disposed end plates 23, so that an end space 29 will be available between the juxtaposed end faces of the two end plates and their adjacent shaft stubs. This arrangement insures the subsequent floating action during operation of the apparatus wherein the timing shaft 26 will be free to axially move back and forth in the direction of the double-headed arrow 30 in FIG. 1, thereby precluding axial loading of the bearings 2.

An important feature of the present invention is that all of the structure described up to this point comprises concentric elements, that is, the timing shaft and its stub portions are cylindrical, as are the tapered sleeves and the referenced components of the rotary drive housing, all of which structure is duplicated at the two opposite side portions of the screening apparatus. The vibratory motion is produced by means of a counterweight assembly, generally designated 31, which is rig-. idly attached to the exterior of the rotary drive housing 14. This assembly includes an eccentric sling member 32 within which are disposed a plurality of weight plates 33, the size and number of which are selected to provide the desired throw to the drive housing 14 as it is rotated. When the selected number of weight plates 33 are assembled within the sling member 32, suitable anchoring means such as the bolts 34 are employed to retain the weight plates in the position shown in FIGS. 1 and 2. For safety purposes during operation of the apparatus, a suitable shield 35 comprising a metallic housing is fixedly mounted by any suitable means to provide a protective barrier encompassing the area of the counterweight assembly 31 as it is rotated about the fixed bearing tube 4.

As is well known in the art, motor driven belts are usually employed to rotate the drive means in a vibrating screening apparatus. In order to accommodate the belt means, a drive sheave 36 is rigidly attached to the outer face of the outside end wall 15 of the drive housing 14 by removable means such as the threaded bolts 37, which bolts may also serve to retain in assembled position, the sheave 36, and the three components 15, 16 and 17 of the drive housing. The sheave 36 includes an inwardly directed flange 38 through which the bolts 37 pass and, when in the installed position as shown in FIG. 1, the inner periphery 39 of the flange 38 will be seen to abut a recessed shoulder 40 provided in the outside end wall 15 of the drive housing. The opening provided by the periphery 39 of the sheave flange 38 is preferably eccentric with respect to the center axis of the sheave 36 in order to provide the off-center attachment of the'sheave to the housing in the manner illustrated in FIG. 1 wherein it will be seen that the greater mass of the sheave is located at the same point as the .counterweight assembly 31 in order to reduce vertical displacement of the belt means engaging thesheave during the orbital movement of the drive housing as the screening apparatus is being driven.

The subsequent alignment of the two opposite drive housings 14 and their respective counterweight assemblies 31 is achieved by means of the guide opening 25 heretofore described which passes through the two end plates 23. After initially assembling one tapered sleeve 19 and its related end plate 23, a drill is passed through the guide opening 25 and into the body of the underlying tapered sleeve 19, whereafter a locator pin 25A is driven through the guide opening 25 and into the bore provided in the tapered sleeve 19. It will be seen that by means of this locator pin 25A all of the components at that side of the screening apparatus are positively lowed, that is, an opening is drilled into the second ta-- pered sleeve for the reception of a locator pin 25A for the purpose of interlocking all of the components at that side of the machine. After installation of each locator pin 25A, a large flat washer 41 may be placed under the fastener 24 adjacent thereto in order to retain each locator pin in its locked position as shown in the drawing.

Means are provided to permit lubrication of both the bearings 2 and splined floating timing shaft connection.

The peripheral or side wall 16 of the drive housing 14 includes an interior lube passageway 42 which communicates with ports 43 through the outer race 5 leading to each bearing cavity. Lubricant may be supplied to the passageway 42 by means of a suitable fitting 44 mounted through the sheave flange 38 and outside end wall 15. Axial displacement of the bearing inner race 3 is precluded by a stop ring 45 axially locked against the tube mounting rate 8 by the oppositely disposed retainer nut 46. Stop ring 45 includes adequate seal means for containing the lubricant within the bearing cavity during rotation of the drive housing. Additionally, a lube fitting 47 is provided in the sleeve end plate 23 to permit the application of a suitable lubricant within the end space 29 between the two splined elements.

I claim:

1. A vibrating screening apparatus including, a screen frame having opposite side walls, a support tube provided with a concentric outer portion extending beyond each said side wall and anchored with respect thereto, a bearing having inner and outer races concentrically mounted upon the periphery of said tube outer portion, a rotary concentric drive housing carried by said bearing outer race, said housing including an outside end wall overlying the outside end of said support tube, a driven cross timing shaft horizontally extending between said frame side walls and concentrically disposed within said support tube, said shaft having distal stub portions provided with axes common with the axis of said shaft and respectively connected concentrically to said housing outside end walls, said shaft connections comprising means preventing independent arcuate displacement between said shaft and housings while allowing free longitudinal displacement of said shaft relative to said housings, eccentric mass means attached to said housings, and means on one said housing for rotating same whereupon said eccentric mass means imparts vibration in turn and concurrently to said housings, support tube, cross timing shaft and screen frame without axial loading of said bearings as said shaft is ,free to axially float due to said shaft connections and without any relative radial displacement I outside end wall and engageable with said shaft stub portion adjacent thereto, and means arcuately adjustably locking said sleeve to said end wall.

4. A vibrating screening apparatus according to claim 9 wherein, said sleeve is provided with a tapered outer periphery, said end wall including a tapered bore mateable with said sleeve tapered periphery, longitudinal splines on the inner periphery of said sleeve and said shaft connection means includes splines on said stub portions engageable with said sleeve splines.

5. A vibrating screening apparatus according to claim 4 wherein, said locking means includes an end plate overlying said sleeve, fastener means attaching said end plate to said housing outside end wall, and removable means locking said end plate to said sleeve to preclude relative arcuate movement therebetween.

6. A vibrating screening apparatus according to claim 4 werein, the axial distance between the outer-most ends of said sleeves is greater than the axial length of said timing shaft.

7. A vibrating screening apparatus according to claim 1 werein, said housing rotating means comprises a drive sheave attached to said outside end wall.

8. A vibrating screening apparatus according to claim 7 wherein, said sheave periphery is eccentric with respect to said housing end wall and the greater mass thereof is disposed in the radial direction of said housing attached eccentric mass means.

5:"UN1'TED STATES PATENT OFFICE v CERTIFICATE 0 CORRECTIQN Pat zen; Nd. 3,768,647 1).ated Qctober'30, 1973 v lnven brgsy Ggi ralld D. Johnson 1 It is certified 'thait err'orr appearsin the above-identifiedpatent I and thatsaid Letters Patent are hereby correc'z ted as shown below:

I I In the heading. of the patent, "Assiqne" I hnge P a rteC| Inc; to Ear-t Signed and sen-alga 5513 19th y or Februar 197M.

(SEAL) I Attest':

. EDWARD M- H J I I MARSHALL DANN \Attgsting' Officer I Commissioner of Pafcents USCOMM-DC 603764 69 1: u.s. GOVERNMENT PRINTING orncz: n0 o-su-su.

FORM PO-105O (10-69) 

1. A vibrating screening apparatus including, a screen frame having opposite side walls, a support tube provided with a concentric outer portion extending beyond each said side wall and anchored with respect thereto, a bearing having inner and outer races concentrically mounted upon the periphery of said tube outer portion, a rotary concentric drive housing carried by said bearing outer race, said housing including an outside end wall overlying the outside end of said support tube, a driven cross timing shaft horizontally extending between said frame side walls and concentrically disposed within said support tube, said shaft having distal stub portions provided with axes common with the axis of said shaft and respectively connected concentrically to said housing outside end walls, said shaft connections comprising means preventing independent arcuate displacement between said shaft and housings while allowing free longitudinal displacement of said shaft relative to said housings, eccentric mass means attached to said housings, and means on one said housing for rotating same whereupon said eccentric mass means imparts vibration in turn and concurrently to said housings, support tube, cross timing shaft and screen frame without axial loading of said bearings as said shaft is free to axially float due to said shaft connections and without any relative radial displacement between said shaft, tube and housings during periods of rest, start-up or fuLl operating speed.
 2. A vibrating screening apparatus according to claim 1 wherein, said shaft connection means includes longitudinally extending splines on said stub portions.
 3. A vibrating screening apparatus according to claim 1, including a sleeve insertable through said housing outside end wall and engageable with said shaft stub portion adjacent thereto, and means arcuately adjustably locking said sleeve to said end wall.
 4. A vibrating screening apparatus according to claim 3 wherein, said sleeve is provided with a tapered outer periphery, said end wall including a tapered bore mateable with said sleeve tapered periphery, longitudinal splines on the inner periphery of said sleeve and said shaft connection means includes splines on said stub portions engageable with said sleeve splines.
 5. A vibrating screening apparatus according to claim 4 wherein, said locking means includes an end plate overlying said sleeve, fastener means attaching said end plate to said housing outside end wall, and removable means locking said end plate to said sleeve to preclude relative arcuate movement therebetween.
 6. A vibrating screening apparatus according to claim 4 wherein, the axial distance between the outer-most ends of said sleeves is greater than the axial length of said timing shaft.
 7. A vibrating screening apparatus according to claim 1 wherein, said housing rotating means comprises a drive sheave attached to said outside end wall.
 8. A vibrating screening apparatus according to claim 7 wherein, said sheave periphery is eccentric with respect to said housing end wall and the greater mass thereof is disposed in the radial direction of said housing attached eccentric mass means. 